A demented Queens dad charged with beating his 2-year-old son into a coma told cops he was too drunk to remember doing it — and failed to get the battered toddler medical help, prosecutors said in court Wednesday. Dayvon Morrison, 30, allegedly beat the boy at a homeless shelter on Friday night and left with the near-death tot the next day, authorities said. The monster dad lugged his wounded son around the Big Apple for three days before a shocked witness noticed the boy’s severe injuries and